High frequency switches are used for passing or blocking high frequency signals. High frequency switches can be realized in different technologies like GaAs technology or MOS technology (MOS=metal oxide semiconductor), however other technologies, like microelectromechanical technologies may be used. High frequency switches are commonly used in all radio frequency applications such as mobile phones.
High data rate systems like UMTS or also new GSM systems bring along the desire to obtain a high precision in impedance matching over a wide range of frequency bands, which leads to a desire for a precise power measurement of high frequency signals, to determine a value of a load impedance of the high data rate systems.